Lobing switch



June 2, 1959 c. F. SCHUNEMANN 2,889,553

LOBING swrrcu Filed Jan. 61, 1956 5 Sheets-Sheet l .June 2, 1959 c. F.SCHUNEMANN 2,889,553

LOBING SWITCH Y Filed Jan. 51, 1956 a Sheets-Sheet a v Fay-5 1 "W V weELY-E ZZZ-U? Y Carl F Sc/zizzemazm I nited LOBING SWITCH Carl F.Schunemann, Euclid, Ohio, assignor to Thompson Ramo Wooldridge, Inc., acorporation of Ohio This invention relates to a lobing switch and moreparticularly to a switch for an antenna lobing system or the like inwhich a movable contact is sequentially connected to a plurality ofstationary contacts.

In order to determine the direction from which a radio signal isreceived, a directional antenna array or a loop antenna may be rotatedthrough 360 in azimuth with the direction being indicated by plottingthe strength of the received signal as a function of the angle ofrotation. However, in certain frequency ranges, such as from 10 to 60megacycles, a directional antenna array may be too cumbersome forconvenient rotation and yet the frequency may be too high for efiicientoperation of a loop antenna. In such a case, a number of directionalantenna elements may be equally spaced about a vertical axis andsequentially connected to a receiver through a switch including one ormore movable contacts sequentially engaged with stationary contactsrespectively connected to the antenna elements.

In such an arrangement, one desirable feature is that the elapsed timein switching from one contact to the next should be as small as possibleand it is also desirable that the coupling between the stationarycontacts be as small as possible to minimize cross-talk. It is furtherdesirable, of course, that the switch be simple, compact, efiicient andreliable in operation and constructed of parts which are readily andeconomically manufactured and assembled. It is therefore the object ofthis invention to provide a switch having these desirable features.

According to this invention, a movable contact is driven in such amanner that its speed of movement is relatively low while it is inengagement with each stationary contact and relatively high when movingbetween the stationary contacts. With this arrangement, the elapsed timein switching between contacts is minimized and at the same time thestationary contacts may be spaced apart a substantial distance tominimize coupling therebetween.

Any variable speed drive arrangement could be used but preferably, asupport element is arranged to be driven in such a manner that a pointthereof moves in a path generally parallel to an imaginary lineinterconnecting adjacent stationary contacts, and means are providedresiliently urging the movable contact away from such point toward aposition beyond such imaginary line. With this simple arrangement, thesupport element may be driven at a constant speed and the resilientmeans stores up energy while the movable contact engages a stationarycontact with the stored energy being released to snap the movablecontact into engagement with the next stationary contact. In addition,the pressure exerted between the contacts and the wiping action obtainedbetween contacts minimizes contact resistance and insures reliableswitch operation.

The support element is preferably rotatable with the stationary contactsarranged in arcuately spaced arrangement about the axis of rotation ofthe support element, and the movable contact is preferably carried by anarm s Patent 2 of resilient material so as to provide a very simple andyet efficient and reliable construction.

This invention thus provides a switch which is very simple inconstruction and yet highly efiicient and reliable in operation. Theswitch has general application but is particularly advantageous in anantenna lobing system because of the fact that the elapsed time inswitching between contacts is minimized while the contacts may be spacedapart a substantial distance to minimize coupling therebetween.

This invention contemplates other objects, features and advantages whichwill become more fully apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings which illustrate apreferred embodiment and in which:

Figure 1 is a side elevational view of an antenna assembly incorporatinga lobing switch constructed according to the principles of thisinvention;

Figure 2 is an elevational sectional view through the switch of theassembly of Figure 1;

Figures 3, 4 and 5 are sectional views respectively taken substantiallyalong lines III-III, IVIV and V-V of Figure 2; and

Figures 6 and 7 are sectional views respectively taken substantiallyalong lines VI-VI and VII-VII of Figure 5.

Reference numeral 10 generally designates an antenna assembly in which alobing switch unit 11 constructed according to this invention is used tosequentially connect the input of a receiver to a plurality of antennaelements 12. The switch unit 11 is supported at the upper end of a mast13.

Each of the antenna elements 12 is secured to a hooked end portion 15 ofa conductor 16 embedded in a support ring 17 of insulating material suchas plastic with the conductors 16 extending radially in angularly spacedrelation like the spokes of a wheel. The inner end of each conductor 16is soldered to a lug 18. Screws 19 extend through the lugs 18 andthrough tubes or sleeves 21, with the ends of the screws 19 beingthreaded into a support ring 22 of insulating material which issupported on a flange ring 23 secured in assembly with the ring 17.

The tubes or sleeves 21 form stationary contacts and are disposed inspaced relation in a circle about the axis of the shaft of an electricdrive motor 24 supported on the flange ring 23.

The motor shaft 25 is coupled by a pin 26 to one end of a coupling shaft27 the other end of which is coupled to the shaft 28 of a synchro torquetransmitter 29 which generates a signal for the remote indication of theangular position of the shaft 28 and elements coupled thereto. Thetransmitter 29 is secured within a base 30 of invetted cup-shapedconfiguration which is slipped on the end of the mast 13. The ring 17 issupported from the base 30 through a bearing plate member 31 of invertedcup-shaped configuration which is also used to support a ball bearingassembly 32 for the coupling shaft 27.

A collar 33 is secured on the coupling shaft 27 and carries a ring 34 ofinsulating material. As shown in Figures 3 and 4, the ring 34 has a pairof blocks 35 and 36 secured to the upper face thereof with outwardlyprojecting arms 37 and 38 being secured at their inner ends to theblocks 35 and 36 and with contacts 39 and 40 secured to the outer endportions of the arms 37 and 38.

The arms 37 and 38 are of a resilient conductive material, preferablyberyllium copper, and are of such length that in the unstressedcondition thereof, the contacts 39 and 40 project outwardly beyond animaginary circle at the inner edges of the stationary contacts definedby the tubes 21. With counter-clockwise rotation of the ring 34 andblocks 35 and 36 secured thereto (as viewed in 3. Figures 3 and 4), thecontacts 39 and 40 will engage a pair of the contacttubes" 21.Witlifurtlier'counteFclo'clG wise rotation, the arms 37 will beresiliently bent back ina clockwise direction and thecontacts 39and v40will slide radiallyinwardly ionf-gthe contact'tubes'lll'i' When the arms37 -and 38are bentto suchian extentthat' the contacts 39 'and40lareinside the contact tubes .21; the arms will be released and theresiliencyjthere'of will snap them forwardly toward the nextpajriofcontact tubes.

Preferably, the position and length. of the arms 37 and 38 is such.relative to the position and spacingof the tubes 21 that when thecontacts 39and 40' teria'lmounted on the underside; jofitl'ie insulatingring 342 and engaged by brushesAS and 44 mounted in slevesAS and 46andurged' into pressure: engagement with the' slip rings 41 and 42 bycoiledcompressionf springs; 47 and 48*within' the sleeves 45 and46whiehare pressediinto insnlator49 'afiixed to thebearing'platefllijThe'sl'eeve 45 is formed to provide a first terminal post50'projectingithrough" the hearingtplatei 31' and the sleeve" 46 isconnected through a wire51' to a secon'd'terminal'post 52 also extendingthrough the bearing plate 31. The

terminal posts 50 and 52 are'cormected through wires 53"and' 54to'terminal posts 55 and '56 insulatingly supported in'the wall ofth'e'bearingplat'e 31, the postsSS and'SG-being arranged forconnectionithrough a' suitable transmissionline"tothennpntterminals of areceiver;

The conductors of a cable 57 connected tofthemotor' 24" and a cable58"connected'to'the-transrnitter 29a're connected to a-jack 59supportedin the wall of the 'hearing plate member 31, and'apluginsertedin'th'ejack 59'may beconnected to a remote unitnot shown'including ,a position indicator'actuated by-the signal fiomthetransmitter 29 and' also 4 including a power supply forth'e motor24'. A capacitor 60in circuit with the-motor 24may be disposed withinthebearing plat'ej member *31: 1

It willbe noted thatin theillustrated antenna assembly,

there are eighteen elements at" equal' spacings of*20 and theterminals55- and 56 whichmay beconnected to*the receiver input are at any giveninstant: connected to a pair of the antenna elements spaced 40 apart so"that the antenna is thus a sloping inverted V with an includedangle"of4(); Such an antenna may have highly directionalcharacteristics, and by plotting the receiver response with respect torotation of the switch assembly, the direction from which a receivedsignal emanates can be accurately determined, It will be apparent thatthe antenna elements may becotany desired length and the unit 11 may beof much smaller size relative to the length of the antenna; elementsthanis the case with the assembly illustrated in Figure 1.

Thisinvention: thus provides a switch which is very simple inconstruction and yet highly efficient andreliable in operation.Thezswitchhas generalapplication'rbut is particularly advantageous in anantenna lobing system because of the fact that the elapsed time inswitching between contacts is at a minimum while the contacts may bespaced apart a substantial distance to minimize coupling Itwill beunderstood that modifications and variations may b'ej; efiected withoutdeparting from the spirit .and-

scope of'the novel concepts of the present'invention.

I claim as myinvention.

Iniarr antenna lobing system; a support ring; of insulatingv'material,8.".Pll1lfilll'Y of angularly spaced radially extending'con'ductors insaid support, ring, a plurality of antenna elements 'connectedtotheouten'ends ofsaidcona ductors' toproject therefrom in radial-planes,aplilrality' of stationary contactsconnectedto theinner ends ofsaidconductors and arranged in aicirclein' equi angularly'spacedrelatiowabout the axis of said ring; a contact" support elementrotatableabout saidaxis, arrelectric drive motor' for effectingcontinuous rotation" of' said support element, a pair of resilient leafspringelements'on said contacts to be simultaneously snapped intoengagement with the next' pair of saidstatibnary' contacts; and slipringme'ans *onsaid support element connecting said pair of springcontact elements to a utilization circuit.-

References-Cited in thefile of this patent UNITED" STATES PATENTS1165,48? Huggins July ll, 1939 2,602,892. Koch t July 8, 1952

